On Mon, 22 Jan 2024 at 23:17, Maciej Fijalkowski
<maciej.fijalkowski@xxxxxxxxx> wrote:
>
> Ice and i40e ZC drivers currently set offset of a frag within
> skb_shared_info to 0, wchih is incorrect. xdp_buffs that come from
Is "wchih" Polish? Just kidding with you ;-)!
> xsk_buff_pool always have 256 bytes of a headroom, so they need to be
> taken into account to retrieve xdp_buff::data via skb_frag_address().
> Otherwise, bpf_xdp_frags_increase_tail() would be starting its job from
> xdp_buff::data_hard_start which would result in overwriting existing
> payload.
Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> Fixes: 1c9ba9c14658 ("i40e: xsk: add RX multi-buffer support")
> Fixes: 1bbc04de607b ("ice: xsk: add RX multi-buffer support")
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/i40e/i40e_xsk.c | 3 ++-
> drivers/net/ethernet/intel/ice/ice_xsk.c | 3 ++-
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> index fede0bb3e047..65f38a57b3df 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> @@ -414,7 +414,8 @@ i40e_add_xsk_frag(struct i40e_ring *rx_ring, struct xdp_buff *first,
> }
>
> __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
> - virt_to_page(xdp->data_hard_start), 0, size);
> + virt_to_page(xdp->data_hard_start),
> + XDP_PACKET_HEADROOM, size);
> sinfo->xdp_frags_size += size;
> xsk_buff_add_frag(xdp);
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index d9073a618ad6..8b81a1677045 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -825,7 +825,8 @@ ice_add_xsk_frag(struct ice_rx_ring *rx_ring, struct xdp_buff *first,
> }
>
> __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
> - virt_to_page(xdp->data_hard_start), 0, size);
> + virt_to_page(xdp->data_hard_start),
> + XDP_PACKET_HEADROOM, size);
> sinfo->xdp_frags_size += size;
> xsk_buff_add_frag(xdp);
>
> --
> 2.34.1
>
>
